Aplomb (7)
'aplomb' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for sang-froid that I've seen before include "18-possession" , "Coolness in adversity" , "Composure in trying circumstances" , "Aplomb" , "Adorns fig, having calmness in danger or difficulty" .)
(Other definitions for panache that I've seen before include "Flamboyant confidence" , "Dash and verve" , "Distinctive elegance" , "'Dash, flair (7)'" , "A dashing manner" .)
'aplomb' is the definition.
(I know that aplomb can be written as poise)
This is all the clue.
(Other definitions for poise that I've seen before include "Physical balance" , "Self-confidence" , "Coolness and composure under strain" , "cool" , "Dignity; equilibrium" .)